1. Field of the Invention
The present invention relates to alpine ski boots whose upper is at least partially journalled with respect to the shell base and relates more particularly to boots comprising a rear spoiler or tightening collar, for the lower leg pivotably mounted in the zone of the heel on the shell base and angularly blockable with respect to the latter in the position of closure of the upper.
2. Description of Background and Relative Information
Known ski boots of this type have a tightening collar of for the lower leg which is angularly blockable with respect to the shell base in the front-rear direction by means of a latching apparatus positioned for a portion on the collar and for another portion on upper and lateral extensions of the shell base extending in the zone superior to the malleoli. One can in particular cite ski boot models in which the latching apparatus is constituted by a projection, carried by the extensions of the shell base and by a corresponding nesting opening provided on the collar, such as is taught in Italian Patent 1,087,581. In these boots the wings of the collar are spaced render the latching apparatus inoperative and allow for the rocking of the collar towards the rear for putting on and taking off the boot. Conversely, by maintaining the wings of the collar tightened on the extensions of the shell base by means of the closure system of the upper on the lower leg, the latching apparatus then blocks the collar with respect to the shell base in extreme angular position for retention of the lower leg of the skier in the front-rear direction. It follows that the quality of the rearward support of the lower leg on the collar is dependent upon the rigidity of the closure system of the upper, of the vertical extensions of the shell base and of the tightening collar for the lower leg.
Thus, for these types of boots, the tightening and/or retention functions of the lower leg which the various constituent portions of the boots must fulfill are not always achieved in a satisfactory manner for the skier. In effect, the different constituent portions of the upper must have contradictory characteristics to achieve the functions explained above. Yet, the existing boots illustrate that their constructional arrangements only imperfectly have such contradictory characteristics, such that one of the functions sought is achieved to the detriment of the other. Thus, the latching apparatus positioned at the level of the upper flexible extensions of the shell base does not make it possible to obtain the rigidity of the upper which is sought during skiing. This phenomenon is further often aggravated by virtue of the fact that the extensions of the shell base are covered by the wings of the collar which are necessarily flexible. Furthermore, the lower edges of these wings, which are generally raised on the sides of the boot, are exposed to ski edge hits during skiing. Finally, the latching apparatus being situated in a fixed manner on the vertical extensions of the shell base and on the wings of the collar, the angular retention position of the lower leg of the skier in the front-rear position is determined in an unalterable manner, which does not allow for an personalized adaptation responding to the requirements of advanced skiers in particular.